Field of the Invention
The present invention relates to control systems for a room air conditioner and/or heat pump and, more particularly, to a universal control system that can be used on any size room air conditioner and/or heat pump.
Description of Related Prior Art
Air conditioning can refer to any form of cooling, heating, ventilation, dehumidification, disinfection, or anything else that modifies the condition of air. Most people think of the terms “air conditioner” as referring to the cooling of air. Various forms of air conditioning have gone back as far as the second century in the Han Dynasty. British scientist and inventor Michael Faraday discovered that ammonia could be compressed into a liquid and allowed to evaporate to give a cooling effect. One of the earliest electric air conditioning units was invented by Willis Havilan Carrier, after whom the large heating/cooling company of Carrier Corporation is named.
Because ammonia was a toxic flammable gas, other products such as chlorofluorocarbon (CFC) were developed with a brand being marketed by DuPont Corporation becoming known as Freon. Over the years, different types of refrigerant have been developed with some refrigerants being designed particularly for heat-pump systems.
A heat-pump has the ability to bring heat into a room or to take heat out of a room. In the air conditioning cycle, the evaporator absorbs heat from inside the house and rejects the heat outside through a condenser. The condenser is located outside the space being cooled and an evaporator is located inside the space being cooled. The key component that makes a heat pump different from air conditioner is the reversing valve. The reversing valve allows for the flow direction of the refrigerant to be changed. This allows the heat to be pumped either into the space being conditioned or outside of the space being conditioned.
In the heating mode, the outdoor coil becomes the evaporator while the indoor coil becomes the condenser. The condenser dissipates the heat received from the refrigerant due to the air flowing there through and into the space to be heated. With the refrigerant flowing in the heating mode, the evaporator (outdoor coil) is absorbing the heat from the air and moving it inside. Once the refrigerant accepts heat, it is compressed and then sent to the condenser (indoor coil). The indoor coil then gives off the heat to the air moving there through which in turn heats the room being conditioned.
In the cooling mode, the outdoor coil is now the condenser and the indoor coil is the evaporator. The indoor coil will absorb heat from the air moving there through which cools the air being delivered to the room being conditioned. The condenser takes the heat from the refrigerant and transfers the heat to the outdoor air.
Heat pumps are normally used in more temperate climates. The reason for use in temperate climates is due to the problem of the outdoor coil forming ice which blocks airflow during the heating cycle. To compensate for icing during colder weather, a heat pump will have to temporarily switch back into the regular air conditioning mode to de-ice the outdoor coil. Rather than having cold air being discharged inside the space to be heated, a heating coil is switched on to heat the air being delivered through the inside coil to the space to be heated.
In the past, heat pumps were basically used in central air conditioning systems. A few of the more expensive window air conditioning units had the heat pump function. However, prior window mounted heat pumps had a number of drawbacks that are satisfied with the present invention.
In a window air conditioning unit or a through the wall system, normally everything is contained within the single unit. The exception might be the thermostat could be located at a remote location within the room to be heated or cooled. Otherwise the indoor coil, outdoor coil, compressor, reversing valve, motors, fans and expansion device are all contained within a unit. That unit which is powered by electricity, must have suitable controls for operation of the unit plus give good air distribution within the space to be heated or cooled.
Control systems for prior room air conditioners and/or heat pumps do not have the number of sensor inputs as the present invention, nor the number and/or type of functional controls as is provided by the present invention. By use of an electronic control system with a microprocessor in a user interface connected to a microcontroller for the main control, a large number of different control options can be programmed into the electronic control system. While in the past, a large number of different control options were available in central air conditioners, even the control system as used in central air conditioners are not as extensive as control options of the present invention.
Prior art known by Applicants does not have all the sensory inputs into an electronic control system that controls the air condition/heat pump functions in as many ways as the present invention.
In addition to the internal controls, the present electronic control system can (a) be connected to a remote control through an infrared detector, (b) a wall-mounted thermostat and/or (c) have a serial port that can be used for programming diagnostics or maintenance. The combination of these features are not shown in room air conditioners and/or heat pumps.